No shadow when stroke is painted first

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/2.3.4/fabric.min.js"></script>
<canvas id="c" width="400" height="400" class="c"></canvas>

CSS

canvas {
  border: 1px solid grey;
}

JavaScript

var canvas = new fabric.Canvas('c');

var imageSrc = "http://fabricjs.com/assets/dragon.jpg";

fabric.Image.fromURL(imageSrc, function(img) {
  img.set({
    left: 10,
    scaleX: 0.18,
    scaleY: 0.18,
    top: 10,
    strokeWidth: 50,
    stroke: '#ccc',
   paintFirst: 'fill'
    
  }, {
    crossOrigin: 'anonymous'
  });

  img.setShadow({
    color: 'rgba(0,0,0,0.3)',
    offsetX: 50,
    offsetY: 50,
    blur: 50
  });

  canvas.add(img);
});